An apparatus for displaying a display screen image of an external device is well known as a vehicular apparatus. For example, patent literature No. 1 teaches the apparatus. The apparatus in patent literature No. 1 displays a screen image of a cell phone as the external device on a display unit of a vehicle. Further, in patent literature No. 1, the vehicular apparatus distinguishes the content of the information in the screen image of the cell phone. Specifically, the apparatus identifies traffic information, motion picture information or music information. Thus, the apparatus changes the dimensions of the screen image of the cell phone to be displayed on the display unit of the vehicle, or does not display the screen image, according to the information of the screen image and a driving status of the vehicle. In order to perform the identification with the vehicular apparatus, information for the identification is added to the image data on a cell phone side.
Further, technique is proposed such that, even if an application program of a mobile terminal is not installed in the vehicular apparatus, the display unit of the vehicular apparatus can display the screen image of the mobile terminal, and further, the mobile terminal is operable with the operation from the vehicular apparatus (e.g., a touch operation of the screen). For example, a terminal mode is well known as a standard for the technique. Here, although the terminal mode is an example of the above described technique, the terminal mode represents a generic term of the above described technique in the present description.
In the terminal mode, the vehicular apparatus is used for a screen image display unit and an operation unit of the mobile terminal. Thus, it is not necessary, in general, to install the application program of the mobile terminal in the vehicular apparatus. Further, the information transmitted from the mobile terminal to the vehicular apparatus is, in general, only color information of each picture cell (i.e., picture cell information). In the terminal mode, even if the application program of the mobile terminal (that is simply defined as an application program) is not installed in the vehicular apparatus, the vehicular apparatus can utilize the function of the mobile terminal. Thus, advantages are obtained such that the process load of the vehicular apparatus is reduced.
As described above, in the terminal mode, the information transmitted from the mobile terminal to the vehicular apparatus is only the picture cell information, in general. Further, as described above, the application program of the mobile terminal is not installed in the vehicular apparatus. Accordingly, it is difficult for the vehicular apparatus to add a function to the application program under a condition that the application program of the mobile terminal is executed, and the screen image of the application program is displayed on the vehicular apparatus.
For example, in patent literature No. 1, the information for identification to identify a type of the image data is attached to the image data, and then, the information is transmitted to the vehicular apparatus. However, in the terminal mode, the information for identification is not transmitted, in general. Thus, as described in patent literature No. 1, it is impossible to change the dimensions of the screen image of the cell phone to be displayed on the display unit of the vehicle according to the information for identification.
Further, recently, multiple mobile terminals having a navigation function (i.e., a road guidance function) are well known. It is considered that the navigation screen image of the mobile terminal may be displayed on the display unit of the vehicle in the terminal mode. In this case, similar to a vehicular navigation apparatus, while driving, the display unit displays a road map, and it is preferable to restrict a part of functions (such as a touch switch operation). When the touch switch operation is restricted, the vehicular navigation apparatus maintains the display color of the road map, and changes the color of the touch switch (e.g., reduces a color tone) to be a color indicative of non-operable status. However, in the terminal mode, as described above, in general, only the picture cell information is transmitted from the mobile terminal to the vehicular apparatus, so that data indicative of the touch switch is not transmitted. Accordingly, in the terminal mode, it is impossible for the vehicular apparatus to change and display a part of the screen image of the mobile terminal according to the conventional art.
Further, it is considered that it is requested to add various functions, with using the vehicular apparatus side, to the application program executed by the mobile terminal under a condition that the screen image of the mobile terminal is displayed on the vehicular apparatus in the terminal mode. However, in the terminal mode, difficulty arises such that it is impossible to add various functions such as a driving restriction function, with using the vehicular apparatus side, to the application program executed by the mobile terminal according to the conventional art.